Looks like MTV Games and EA have some overstock from last year they'd like to move:

Just in time for the holidays, Harmonix, the world's leading developer of music-based games, MTV Games, a part of Viacom's MTV Networks (NYSE: VIA, VIA.B), and distribution partner Electronic Arts (NASDAQ: ERTS) today announced that the original Rock Band Special Edition Bundle is available for the PLAYSTATION®2 computer entertainment system and Wii™ starting at $99.99. The Rock Band Special Edition Bundle is also available for the Xbox 360® video game and entertainment system from Microsoft and PLAYSTATION®3 computer entertainment system and starting at $139.99.

A must have-gift for any music or game fan, Rock Band is an all-new way for people to connect with the music they love in a social, interactive environment. The Rock Band Special Edition Bundle gives families and friends everything they need to start their own band - a microphone, Fender Stratocaster-modeled guitar controller and drum controller. -- Press Release

So, if you were holding out on the Wii version of the first game for any reason, I guess this means that now is your chance to pick it up for less. Don't think PS3/360 version is seeing much of a markdown, though.